1. Field of the Invention
The present invention relates generally to archery and more specifically to a multi-element one piece crossbow frame, which includes a riser and a barrel fabricated from a single piece of material.
2. Discussion of the Prior Art
It is a common product design goal to improve or replace conventional items with items having improved characteristics, such as improvements in strength, rigidity and durability, material qualities and economic concerns. One industry where such enhancements are being made is the crossbow industry. Crossbows have multiple elements, such as a trigger assembly; a bow assembly, which may include a bow riser, limbs, cams and a string and cable set; a frame, which may include a barrel, also known as a flight rail, a foot stirrup; and a stock assembly. The bow assembly is generally attached to the frame assembly, and the trigger assembly is generally inserted into the frame assembly. Some of the base elements of the assemblies typically consist of a bow riser, limb pockets, barrel, and stirrup, that when joined together, form what can be called a crossbow frame. Typically, some sort of mechanical fastening is used to join the elements of the crossbow frame together, which may cause unwanted stress on the connection points. Stresses of varying magnitude and orientation develop within the crossbow frame during use. Stresses can also develop within the frame components during the manufacturing process.
One example of prior art is U.S. Pat. No. 7,258,113 to Pilpel et al., which teaches an archery riser formed from a fibrous composite material, and which may incorporate a spine formed from a different material than the rest of the riser. This method may also include a near net shape, which requires additional machining to achieve the final desired shape. Though this method achieves its desired goal, these methods can be improved upon.
Another example of prior art is U.S. Pat. No. 8,807,125 Mathur, et al, which teaches a three dimensionally fiber reinforced composite riser and methods of making the same. U.S. Pat. No. 8,807,125 is hereby incorporated by reference into this application in its entirety. This method for manufacturing a crossbow riser is ideal. However, Mather et al. is limited to the scope of a crossbow riser, which may or may not include the limb pockets. Whether utilizing a riser machined from a near net shape composite, or a riser made of a three dimensionally reinforced composite, mechanical fasteners are still required to join the riser with other components of the crossbow frame. These fastening points create weakness, and a potential source of noise and vibration, caused from multiple surface irregularities and imperfections. Additionally, all of these other components of the crossbow frame each require their own tooling and manufacturing process.
Accordingly, there is a clearly felt need in the art for a exists a need for a multi-element one piece crossbow frame, which is created in mold, from a three dimensional fiber-reinforced composite.